@Frozen: While it's true that G&W has some insanely strong KO power, G&W is horrible at landing said KO moves outside of reading (or if the opponent doesn't know how to tech dthrow lol). Yoshi has some... decent kill moves, but there's some other problems of his that hurt him more (like a defective shield that you can't jump out of and has extra shield drop lag).
@ the whole killing arguent: MK's aerial SL gimp is so 2008, if you know how to avoid it, you'll usually get hit by it, but you'll be knocked to the other side, not gimped. MK's grounded SL is a more reliable killer, but that doesn't happen until like 150% lol. Marth's tipper fsmash is powerful, but you really need an almost hard read to pull it off, imo it isn't as reliable upB oos, bair edgeguard traps, utilt/uair, and nair/untipped smashes (dsmash is pretty situational but actually has some really nifty niche uses, for example if MK hits your shield with dsmash, you'll get a tipper dsmash for punish

)
Edit: People also forgot Fox/Luigi for good KO potential, although most bad foxes are bad at landing usmash/uair because they're really predictable/don't punish like TKD, and Luigi has a hard time getting anywhere, let alone landing a kill (although angled fsmash and jab stuff -> upb are scary good). Olimar's also a fairly good candidate, purple pikmin are pretty beefy for his kill throws/usmash oos.
@mood4food: Snake while having some fast moves and a good DACUS, I wouldn't say DACUS entirely removes his ground mobility, imo DACUS is more of a reset/punishment tool than a directly approach/space enhancing tool. If you've ever watched matches where snake is generally outcamped (ex. Falco or Toon Link), DACUS doesn't work because projectiles stop it, making Snake veeeeeeeeeeeeeeery slow in approaching. It is noteworthy though to say that his damage to move speed ratio is pretty good (4 frame move put together -> 21%? Crazy good).